How to treat the under design poured concrete on shearwall? example: the designed strength of concrete (f’c) must be 7000 psi however it was poured by only f’c=5000psi?
There could be broadly two types of corrective treatment: a. Support the concrete column with adjoining steel column ( an ISMB section will be better.), for ordinary house 12 feet height column, suggested steel ISMB is 250X 150 mm section. b. if column is found reparable, it is renovated with ‘ JackRead more
There could be broadly two types of corrective treatment:
a. Support the concrete column with adjoining steel column ( an ISMB section will be better.), for ordinary house 12 feet height column, suggested steel ISMB is 250X 150 mm section.
b. if column is found reparable, it is renovated with ‘ Jacketing ‘ around it. That is, scarp old peeling plaster, reach to reinforcing material, apply corrosive preventive liquids available from a good hardware store. Then, tie new reinforcement over the old reinforcement. Over it place 4-inch fresh cement concrete with aggregate of 12mm. Of course, steal or wooden scaffolding will be required.
It will increase the size of the column but will give strength to it.
BUT Note: if the column has already buckled down.. it is advisable to immediately get the help of an engineer and show him the site because if the column collapses, building or roof over it is in danger.
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Komal Bhandakkar
Design of poured concrete on the shear wall: When the final f'c extrapolated from a break of 3 days then an additional break of 5 days (it is usually 3, 7 & 28 days), it is directly indicated that the first cylinder itself was defective. When the f'c of 5000psi was one of the 28th day (i.e. finaRead more
Design of poured concrete on the shear wall:
But after all, the testing fell short of the design, the general contractor, and batch plant manager approach to the officer in charge (Airforce colonel which is assigned to oversee the project) to propose one of the serious field testings to demonstrate that the cantilever would work.
Finally, he decided to redo it.
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